A non-aqueous electrolyte secondary battery such as a lithium-ion battery is used as a power source for portable devices such as mobile phones, laptop computers, and PDAs.
As for types of electrode assemblies used in lithium-ion batteries, there are two types, one being a spiral electrode assembly, in which a positive electrode plate and a negative electrode plate are spirally wound with a separator therebetween, and the other being a stacked electrode assembly, in which a plurality of quadrilateral electrodes are stacked one on top of another. Further, as an outer casing for a lithium-ion battery, a laminate casing composed of laminate film that is formed so as to have a cup-shape is used.
As disclosed in Patent Literature 1, such a laminate battery is manufactured by disposing, so as to be contained in a laminate casing formed to have a cup-shape, a flat electrode assembly and a non-aqueous electrolyte and by weld sealing the laminate casing while putting an interior of the laminate casing in a reduced pressure state.
Furthermore, laminate batteries having large sizes, which are used as drive power sources for driving robots, electric vehicles, etc., are being manufactured.